Apparatus for providing controlled impedance in an electrical contact

ABSTRACT

An apparatus for providing a controlled impedance directly to predetermined contact elements within a socket, thereby reducing the “distorting” nature of the electrical interconnection system. In an illustrative embodiment of the present invention, predetermined contacts of a socket may have a resistance, inductance, capacitance, or a combination thereof incorporated therein. In another illustrative embodiment, at least one active element(s) may also be incorporated into predefined contacts. In this manner, predefined contacts may “process” the corresponding signal in a predetermined manner, defined by the circuitry incorporated on the contact itself. Illustrative functions that may be performed include, but are not limited to, amplifying, analog-to-digital converting, digital-to-analog converting, predefined logic functions, or any other function that may be performed via a combination of active and/or passive elements including a microprocessor function.

TECHNICAL FIELD

[0001] The present invention is related to electrical interconnectsystems and more particularly relates to high performance electricalinterconnect systems which provide signal conditioning therein.

BACKGROUND OF THE INVENTION

[0002] A plethora of applications exist for effecting electrical contactbetween two conductors. Examples of such applications include cableconnectors, PC board connectors, socket connectors, DIP carriers, etc.In an illustrative application, an interconnect system may effect aninterconnection between a number of terminals on a first printed circuitboard with a number of corresponding terminals on a second printedcircuit board. Such apparatus are used to provide an electricalinterface between two circuit boards. In another illustrativeapplication, an interconnect system may effect an interconnectionbetween a lead of an integrated circuit device and a conductive pad orterminal on a printed circuit board. The circuit board may then becoupled to a tester apparatus or other control means. Such apparatus areused to evaluate the performance of integrated circuit devices.

[0003] Numerous considerations bear upon the structure of an electricalinterconnect system, including both electrical and mechanicalconsiderations. For typical interconnection systems, special attentionmust be given to the electrical performance thereof including selfinductance, resistance, capacitance, impedance matching characteristics,etc. Mechanical considerations including life span requirements,repairability or replacability, operating temperature requirements,etc., must also be considered. Finally, specific applications of anelectrical interconnect system may yield a number of unique parameterswhich must also be considered. For example, in an interconnect systemwhich provides an electrical interconnection between an integratedcircuit lead and a printed circuit board terminal, various parametermust be considered including the coplanarity of the terminals, themechanical manufacturing tolerances, and the device alignment andorientation of the device terminals relative to the interconnectionsystem.

[0004] A main objective of an interconnection system is to maintain anon-distorting electrical interconnection between two terminals. Toaccomplish this, an interconnection system must be carefully designed tocontrol the lead inductance and resistance, the lead-to-leadcapacitance, the lead-to-ground capacitance, the electrical decouplingsystem, and the impedance matching characteristic of signal paths. Allof these characteristics contribute, to some degree, to the distortingnature of the electrical interconnection system.

[0005] Various methods have been developed to help minimize theparasitic effects of the interrconnect system. A common method is toprovide signal condition circuits adjacent the electromechanicalcontacts of the electrical interconnection system. The signalconditioning circuits, typically discrete elements such as terminationcomponents are used to adjust and control the circuit impedance. Becausethe requisite signal conditioning components and electromechanicalcontacts are physically separated, it is difficult to attain an idealinterconnect system, thereby compromising the accuracy, precision andreproducibility of the interconnect system.

[0006] One prior art structure is suggested in U.S. Pat. No. 4,260,762,issued on Apr. 29, 1975 to Lockhart, Jr. Lockhart suggests a test socketfor interconnecting a dual-inline integrated circuit package and aprinted circuit board. A capacitor is provided in the body of the socketwherein the socket material provides the dielectric for the capacitor.The contacts of the capacitor are in contact with the socket connectors,which are in turn in contact with the integrated circuit package. Thatis, Lockhart suggests a test socket wherein the capacitor is provided inthe socket body, rather than on the “load board” as previouslydiscussed.

[0007] A scheme to connect a first circuit board containing a testsocket to a coaxial probe card, and eventually to an IC tester issuggested in U.S. Pat. No. 4,996,487, issued on Feb. 26, 1991 to Pope.The first circuit board has an integrated circuit test socket connectedthereto and traces from the integrated circuit test socket to platedthrough-holes and further to blind vias. The coaxial probe card thenengages the blind vias to provide an electrical communication pathbetween the IC tester and the integrated circuit test socket.

[0008] A method for reducing noise in a telephone jack is suggested inU.S. Pat. No. 4,695,115, issued on Sep. 22, 1987 to Talend. Talendsuggests a modular jack for telephones in which discrete bypasscapacitors are connected to the leads of the jack to filter out noisethereon. Talend contemplates using monolithic surface mount capacitorswhich extend to a ground plane in the modular jack element.

[0009] The use of a pi-network to reduce noise in a connector issuggested in U.S. Pat. No. 4,853,659, issued on Aug. 1, 1989 to Kling.Kling suggests using a planer pi-network filter comprising a pair ofshunt capacitors and an inductive member in series therebetween. Klingcontemplates using the pi-network filter in combination with cableconnectors or the like.

[0010] A millimeter-wave probe for use in injecting signals withfrequencies above 50 GHz is suggests in U.S. Pat. No. 4,983,910, issuedon Jan. 8, 1991 to Majidi-Ahy et al. In Majidi-Ahy et al. an inputimpedance matching section couples the energy from a low pass filter toa pair of matched, anti-parallel, beam lead diodes. These diodesgenerate odd numbered harmonics which are passed through the diodes byan output impedance matching network.

[0011] Finally, a capacitively loaded probe which can be used fornon-contact acquisition of both analog and digital signals is suggestedin U.S. Pat. No. 5,274,336, issued on Dec. 28, 1993 to Crook et al. InCrook et al., the probe consists of a shielded probe tip, a probe bodywhich is mechanically coupled to the probe tip, and an amplifier circuitdisposed within the probe body.

SUMMARY OF THE INVENTION

[0012] The present invention overcomes many of the disadvantages of theprior art by providing a means for electrically affecting a signaldirectly within the contact elements of the interconnection system. Itis contemplated that the present invention may be applied to any type ofelectrical interconnect system including, but are not limited to, cableconnectors, PC board connectors, test socket connectors, DIP carriers,etc.

[0013] In an illustrative embodiment, the electrical interconnect systemmay comprise a number of contacts wherein a first portion of eachcontact may be brought into electrical communication with acorresponding first terminal. A second portion of each contact may be inelectrical communication with a corresponding second terminal. Toenhance the performance of the interconnect system, the presentinvention may provide a means for electrically affecting a signaldirectly within predetermined ones of the contacts. This may beaccomplished by providing a controlled impedance therein.

[0014] A number of advantages may be achieved by providing a controlledimpedance directly within the contact element. For example, in anintegrated circuit test application, the maximum benefit of thecontrolled impedance may be achieved by having the controlled impedancelocated as close as possible to the integrated circuit lead. That is,the closer that the controlled impedance is placed to the integratedcircuit lead, the greater the benefit the controlled impedance may haveon reducing the distorting nature of the interconnect system. In thepresent embodiment, the controlled impedance may be coupled directly tothe contacts within a corresponding test socket, rather than beingplaced on an adjacent load board or the like.

[0015] In one embodiment of the present invention, predeterminedcontacts of the socket may have a resistance, inductance, capacitance,and/or surface acoustical wave filer therein. Further, predeterminedcontacts of the socket may have a combination of the above referenceelements, thereby forming a circuit. This additional impedance may beused for impedance matching purposes in order to reduce reflections orother noise mechanisms on a corresponding signal line. Further, theadded impedance may be used to provide capacitive or inductive couplingto signal or power pins. That is, the controlled impedance mayelectrically affect a corresponding signal.

[0016] In another embodiment of the present invention, predeterminedones of the contacts of the socket may contact a number of independentsignal traces on a load board. That is, each contact may electricallycommunicate with a number of independent signals on the load board,including the particular signal trace which corresponds to theparticular semiconductor device lead.

[0017] In another embodiment of the present invention, predeterminedcontacts of the socket may have at least one active element incorporatedthereon. For example, a contact may have a transistor, diode, etc.incorporated therein. Further, a contact may have a combination oftransistors, diodes, resistors, capacitors, inductors, surfaceacoustical wave filters, gates, etc. to form a circuit therein. In thisembodiment, the impedance of the contact may be selectively controlledby another independent signal, as described in the previous paragraph,by the logic level of the contact itself, or other control means.

[0018] It is recognized that the inclusion of an active element into aparticular contact of a socket may have numerous applications. Forexample, a contact having just a single transistor incorporated thereinmay be used to control whether a semiconductor device, the tester, orother element is driving a corresponding signal trace. That is, thesingle transistor may be turned off, thereby substantially increasingthe impedance thereof, such that the tester or other means may drive acorresponding signal trace without overdriving a corresponding output ofthe semiconductor device. Similarly, the single transistor may be turnedon, thereby reducing the impedance thereof to a low level, allowing thesemiconductor device to drive the signal trace back to the tester orother element. This may be especially useful with semiconductor devicesthat have bi-directional input/output pins. It is recognized that thisis only one application of the present invention and that numerous otherapplications are contemplated.

[0019] As stated above, a number of active elements may be incorporatedinto predefined contacts of a socket to form a circuit therein.Inductors, capacitors, and resistors may also be incorporated thereinand combined therewith. In this configuration, predefined contacts may“process” the corresponding signal in a predetermined manner, defined bythe circuitry incorporated on the contact itself. For example, a numberof transistors may be incorporated in a contact wherein the number oftransistor may be arranged to provide an amplifier function. That is,the signal provided by the semiconductor device, the tester apparatus,or other means may be amplified by the contact of the socket. Otherillustrative functions may include, but are not limited to,analog-to-digital converters, digital-to-analog converters, predefinedlogic functions, or any other function that may be performed via acombination of active and/or passive elements including a microprocessorfunction.

[0020] In another embodiment of the present invention, the impedance maybe formed between two components within a connector. For example, twoparallel and adjacent contacts may be separated by an insulatingmaterial thereby forming a capacitance therebetween. One of the contactsmay be coupled to a power supply lead on the semiconductor device whilean adjacent contact may be coupled directly to ground. Thisconfiguration may provide capacitance between the power supply andground, thereby reducing noise on the power supply of the semiconductordevice. This embodiment may also be used to provide isolation betweensignal lines or signal lines and a power supply/ground if desired. Thatis, a contact that is connected to ground may be placed between twosignal contacts to reduce the amount of cross-talk therebetween. Thecontact may be shaped to control the amount of inductance on a givencontact. It should be recognized that this is only an illustrativeembodiment, and that other embodiments which provide impedance betweenat least two components of a connector are contemplated.

[0021] In another embodiment, the controlled impedance may be providedon, or incorporated in, predetermined ones of the plurality of contacts.In the simplest embodiment, a resistance provided by the contact itselfmay be changed by varying the material or the shape thereof. In a morecomplex embodiment, and not deemed to be limiting, a metal substrate(MS) may be utilized to create a controlled impedance on predeterminedcontacts. For example, two or more metal plates may be mechanicallyjoined and electrically insulated from one another in such a way as toform impedance controlled (i.e., transmission line, stripline, and/ormicro-strip) electromechanical contacts. One metal plate may serve asthe signal plane while an adjacent metal plate may serve as anelectrical ground reference. Electrical insulation can be accomplishedby a number of means including, application of thermal-settingdielectric coatings including polyimides, epoxies, urethanes, etc.,application of thermoplastic coatings including polyethylene, etc., orby growing native oxide by anodization or thermal growth. These variedapproaches may allow for control of impedance through a number ofadjustable parameters including the dielectric constant of theinsulating material and the plate separation. Mechanical joining may beaccomplished by a number of means including, suspension by or betweenone or more elastomeric members and/or by referencing of the individualplates or sets of multiple plates within predefined mechanicalconstructs, such as slots within a housing.

[0022] In another embodiment, and not deemed to be limiting, a ceramicsubstrate (CS) may be utilized to create a controlled impedance onpredetermined contacts. For example, patterned metal may be fabricatedon a ceramic substrate in such a way as to yield an impedance controlledelectromechanical contact. In an illustrative embodiment, a conventionalthin-film multi-layer technology may provide a 3-terminal type capacitorwherein the first two terminals correspond to a signal I/O and the thirdterminal corresponds to a ground reference. It is also contemplated thatthe same impedance controlled 3-terminal type capacitor could befabricated by a modified multi-layer thin-film process wherein theconductive phase is deposited on an inert/carrier substrate andpatterned for selective oxidation using chemical anodization, plasmaoxidation and/or thermal oxide growth, yielding conductive metalpatterns within a dielectric. Finally, it is contemplated that theprocess could be repeated N-times to yield a multi-layer active contactstructure of the 3-terminal type capacitor.

[0023] While the last two embodiments primarily provide an illustrativethree terminal capacitor type device, it is envisioned that otherconventional processes may be used to provide resistance, inductance,capacitance, and/or a combination thereof to predetermined contacts. Itis further envisioned that conventional or other processes may be usedto provide other active elements including, transistors, diodes, etc.,and/or a combination thereof to predetermined contacts. Finally, it isenvisioned that conventional or other processes may be used to provide anumber of active and/or passive elements in a circuit configurationwhich may provide predefined functions, including a microprocessorfunction to predetermined contacts. In the above referenced embodiments,the electrical affecting means may be integrated with the contactitself.

[0024] Finally, the connector apparatus comprising the above referencedcontacts may be designed such that each of the contacts may beinterchanged with another contact. This may allow a contact having ainductor to be interchanged with another contact having a resistor. Ascan readily be seen, this may allow the connector apparatus to beconfigurable, even after the connector apparatus has been assembled andis in use. That is, the connector apparatus may be customized for aparticular use, and even changed to accommodate a new use.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other objects of the present invention and many of the attendantadvantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, in which like reference numerals designate like partsthroughout the figures thereof and wherein:

[0026]FIG. 1 is a schematic side view of an active contact coupled to apackaged semiconductor device and an interface board;

[0027]FIG. 2 is a schematic side view of an illustrative embodiment ofthe active contact whereby the active contact provides a capacitancebetween a packaged semiconductor device lead and a ground plane;

[0028]FIG. 3 is a schematic side view of an illustrative embodiment ofthe active contact whereby the active contact provides a diode means tothe connection between a packaged semiconductor device and a terminal onan interface board;

[0029]FIG. 4 is a schematic side view of an illustrative embodiment ofthe active contact whereby the active contact provides a switch means tothe connection between a packaged semiconductor device and a terminal onan interface board;

[0030]FIG. 5 is a top view of an illustrative embodiment of the activecontacts whereby the active contacts are separated by a thinnon-conducting layer to provide impedance therebetween;

[0031]FIG. 6 is a perspective view of the embodiment shown in FIG. 5;

[0032]FIG. 7 is a partial fragmented perspective view of an illustrativeembodiment of the present invention including a packaged semiconductordevice and an interface board;

[0033]FIG. 8 is a perspective view of another embodiment of the presentinvention having native Grown Oxide on a Metal Substrate contact to forma controlled impedance therebetween;

[0034]FIG. 9 is a perspective view of a Metal Dielectric Sandwichembodiment having a Metal Substrate Contact;

[0035]FIG. 10 is a perspective view of a two terminal embodiment havinga Ceramic Substrate Contact; and

[0036]FIG. 11 is a perspective view of a three terminal embodimenthaving a Ceramic Substrate Contact.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037]FIG. 1 is a schematic side view of an active contact coupled to apackaged semiconductor device and an interface board 26. An illustrativeembodiment of the present invention may provide a controlled impedancedirectly to predetermined contact elements within a test socket, therebyreducing the “distorting” nature of the electrical interconnectionsystem. It is further contemplated that the present invention may not belimited to test sockets, but rather may be applied to cable connectors,PC board connectors, test socket connectors, DIP carriers, etc.

[0038] A semiconductor device socket may comprise a number of contactswherein a first portion of each contact may be brought into electricalcommunication with a corresponding lead of a semiconductor device.Another portion of each contact may be in electrical communication witha load board terminal or equivalent and subsequently with a tester ofother test means. That is, each contact may provide a mechanical and anelectrical connection between a load board terminal and a correspondinglead on a semiconductor device. To enhance the performance of thesocket, the present invention may electrically affect a signal byprovide a controlled impedance within predetermined ones of thecontacts. The electrical affecting means may be integrated with thecorresponding contact.

[0039] To obtain the maximum benefit of the controlled impedance whichis added to an interconnect system, it is important to have thecontrolled impedance located as close as possible to the semiconductordevice lead. That is, the closer that the controlled impedance is placedto the semiconductor device lead, the greater the benefits thecontrolled impedance may have on reducing the distorting nature of theinterconnect system. In the present embodiment, the controlled impedancemay be coupled directly to the contacts within the socket.

[0040] In the illustrative embodiment shown in FIG. 1, an active contact10 may be coupled to a lead 14 of a packaged semiconductor 12 viainterface 18. Further, active contact 10 may be coupled to at a loadboard terminal 16 via interface 20. Active contact 10 may also becoupled to at least one other load board terminal 22 via interface 24.Active contact 10 may provide both a mechanical and an electricalconnection between packaged semiconductor lead 14 and load boardterminals 16 and 22.

[0041] In accordance with the illustrative embodiment of the presentinvention, predetermined contacts 10 of the socket may have aresistance, inductance, capacitance, surface acoustical wave filters, ora combination thereof incorporated therein. A combination of resistance,inductance, capacitance, or surface acoustical wave filters may form acircuit therein. This additional impedance may be used for impedancematching purposes in order to reduce reflections or other noisemechanisms on a corresponding signal line. Further, the added impedancemay be used to provide capacitive or inductive coupling to signal orpower pins.

[0042] It is contemplated that predetermined ones of the active contacts10 of the test socket may contact a number of signal traces on the loadboard. That is, each contact 10 may electrically communicate with, andmay be mechanically engaged with, a number of signals traces on the loadboard, including the particular signal trace which corresponds to theparticular semiconductor device lead 14. For example, in the embodimentshown in FIG. 1, active contact 10 may be coupled to a first load boardterminal 16 and a second load board terminal 22. It is contemplated thatactive contact 10 may be coupled to a plurality of load board terminalsin a similar manner.

[0043] It is further contemplated that predetermined contacts 10 of thesocket may have at least one active element incorporated thereon ortherein. For example, active contact 10 may have a transistor, diode,etc., or a combination thereof incorporated therein, thereby forming acircuit. It is further contemplated that a combination of resistance,capacitance, inductance, transistors, diodes, surface acoustical wavefilters, gates, etc. may be incorporated therein to form a circuit. Inthis embodiment, the impedance of the contact may be selectivelycontrolled by another independent signal, as described in the previousparagraph, by the logic level of the contact itself, or other controlmeans. In this embodiment, the active contact may have three ports 18,20, and 24 as shown in FIG. 1.

[0044]FIG. 2 is a schematic side view of an illustrative embodiment ofan active contact 10A whereby the active contact 10A provides acapacitance to an interconnection 28 extending between the packagedsemiconductor device lead 14 and load board terminal 16. In theillustrative embodiment, a capacitor 30 may have a first lead coupled tothe interconnection 28 between the packaged semiconductor device lead 14and load board terminal 16. The capacitor 30 may have a second leadcoupled to load board terminal 22 via interface 24. In thisconfiguration, load board terminal 22 may be grounded, thereby providinga capacitance between the interconnection 28 and ground. FIG. 2 is onlyillustrative, and it is contemplated that active contact 11A maycomprise an inductor, resistor, diode, surface acoustical wave filter,or any other element which provides impedance and/or control thereto. Itis further contemplated that active contact 10A may comprise anycombination of the above reference elements thereby forming a circuit.

[0045] FIGS. 3-4 show illustrative embodiments having active elementsdisposed on active contact 10. FIG. 3 shows a schematic side view of anillustrative embodiment of the active contact whereby an active contact10C provides a diode means 36 between the packaged semiconductor devicelead 14 and load board terminal 16. This configuration allows thesemiconductor device 12 to supply current to load board terminal 16 butdoes not allow current to flow from load board terminal 16 into thesemiconductor device 12. Similarly, FIG. 4 shows a schematic side viewof an illustrative embodiment of the active contact whereby an activecontact 10D provides a switch means between packaged semiconductordevice lead 14 and lead board terminal 16. In the illustrativeembodiment, the switch means may comprise a transistor 40 having a gate,source, and drain. The drain of the transistor 40 may be coupled to thesemiconductor device lead 14 via interface 18, the source of thetransistor 40 may be coupled to load board terminal 16 via interface 20,and the gate of the transistor 40 may be coupled to load board terminal22 via interface 24. In this configuration, load board terminal 22 maycontrol the impedance between load board terminal 16 and semiconductordevice lead 14. Further, active contact 10D may have three ports 18, 20,and 24.

[0046] It is recognized that the inclusion of an active element intopredetermined contacts 10 of a socket may have numerous applications.For example, a contact having a single transistor incorporated therein,as shown in FIG. 4, may be used to control whether the semiconductordevice or the tester is driving a corresponding load board terminal.That is, the single transistor 40 may be turned off by applying anappropriate voltage to load board terminal 22, thereby substantiallyincreasing the impedance of the path from the semiconductor device lead14 to load board terminal 16, such that the tester may drive acorresponding load board terminal 16 without overdriving an output ofthe semiconductor device 12. Similarly, the single transistor 40 may beturned on by applying an appropriate voltage to load board terminal 22,thereby reducing the impedance of the path from the semiconductor devicelead 14 to load board terminal 16, allowing the semiconductor device 12to drive load board terminal 16 back to the tester, or visa-versa. Thismay be especially useful with semiconductor devices that havebi-directional input/output pins. It is recognized that this is only oneapplication of the present invention and that numerous otherapplications are contemplated.

[0047] As stated above, it is further contemplated that a number ofactive elements may be incorporated into predefined contacts 10 of asocket to form a circuit therein. Inductors, capacitors, resistors,and/or surface acoustical wave filters may also be incorporated thereinand combined therewith. In this embodiment, predefined contacts may“process” the corresponding signal in a predetermined manner, defined bythe circuitry incorporated on active contact 10 itself. For example, anumber of transistors may be incorporated in active contact 10 whereinthe number of transistor may be arranged to provide an amplifierfunction. That is, the signal provided by the semiconductor device 40 ortester apparatus (not shown) may be amplified by active contact 10 ofthe socket. Other illustrative functions may include, but are notlimited to, analog-to-digital conversion, digital-to-analog conversion,predefined logic functions, or any other function that may be performedvia a combination of active and/or passive elements, including amicroprocessor function.

[0048]FIG. 5 is a top view of an illustrative embodiment of the activecontacts whereby the active contacts are separated by a thin insulatingmaterial to provide impedance therebetween. FIG. 6 is a perspective viewof the embodiment shown in FIG. 5. In an illustrative embodiment, anumber of “S” shaped contacts may be provided wherein each “S” shapedcontact may engage a corresponding lead of a semiconductor device 138. Afirst hook portion 141 of each “S” shaped contact may engage a firstelastomer element 142. A second hook portion 143 of each “S” shapedcontact may engage a second element 144. The second element 144 may beconstructed from a solid material or an elastomeric material. As a lead137 of a semiconductor device 138 engages a corresponding “S” shapedcontact 135, elastomer element 142 may deform thereby permitting “S”shaped contact 135 to deflect away from the corresponding semiconductordevice lead 137. This may help compensate for non-planer device leads ona corresponding semiconductor device 138.

[0049] Referring to FIGS. 5 and 6, the impedance may be formed betweentwo components within the socket. For example, two parallel and adjacentcontacts 134 and 135 may be separated by an insulating material 136thereby forming a capacitance therebetween. One of the contacts 135 maybe engaged by a power supply pin 137 on a corresponding semiconductordevice 138 while an adjacent contact 134 may be engaged by a ground pin139. This configuration provides capacitance between the power supplyand ground, thereby reducing noise on the power supply of thesemiconductor device 138.

[0050] The present embodiment may also be used to provide isolationbetween signal lines or signal lines and a power supply/ground ifdesired. That is, a contact 137 may be connected to ground and may beplaced between two signal contacts 134 and 140 to reduce the amount ofcross-talk therebetween. The contact may be shaped to control the amountof inductance on a given contact.

[0051] In one embodiment, a first contact 135, an insulating material136, and a second contact 134 may be sandwiched together to form animpedance therebetween. This may be accomplished by using a conventionallamination process. In another embodiment, the first contact 135 and/orthe second contact 134 may have an oxide coating placed thereon. Theoxide coating may be grown on the outer surface of the contacts using astandard oxidation processes. In this configuration, the first contact135 may be brought into direct contact with the second contact 134 whilemaintaining electrical isolation therebetween.

[0052] It is recognized that the above referenced embodiments are onlyillustrative, and that other embodiments which provide impedance betweenat least two components of a socket are contemplated.

[0053]FIG. 7 is a partial fragmented perspective view of an illustrativeembodiment of the present invention including a packaged semiconductordevice and an interface board. As stated above, the controlled impedancemay be provided on, or incorporated in, predetermined ones of theplurality of contacts. In the simplest embodiment, the resistanceprovided by the contact may be changed by varying the material or theshape thereof. In a more complex embodiment, and not deemed to belimiting, a metal substrate (MS) may be utilized to create a controlledimpedance on predetermined ones of the plurality of contacts. Forexample, two or more metal planes may be mechanically joined andelectrically insulated from one another in such a way as to formimpedance controlled (i.e., stripline) electromechanical contacts. Onemetal plane may serve as the signal plane while an adjacent metal planemay serve as an electrical ground reference. Electrical insulation canbe accomplished by a number of means, including, application ofthermal-setting dielectric coatings including polyimides, epoxies,urethanes, etc., application of thermoplastic coatings includingpolyethylene, etc., or by growing native oxide by anodization or thermalgrowth. These varied approaches may allow for control of impedancethrough the adjustable parameters of the dielectric constant of theinsulating material and the plane separation. Mechanical joining may beaccomplished by a number of means, including, suspension by or betweenone or more elastomeric members and/or by referencing of the individualplanes or sets of multiple planes within pre-defined mechanicalconstructs such as slots within a housing.

[0054] Essentially any metal may be used for this embodiment of theactive contact. Aluminum is a preferred material since it is readilyanodizable, and yields a good quality and well-characterized dielectricfilm. Other metals that may be used include, but are not limited to,copper and copper alloys, steels and Ni—Fe alloys, NiCr alloys,transition metals and alloys, and intermetallics. Some of thesenon-traditional contact metals may be useful either in a plated ornon-plated embodiment to adjust and control the contact's bulkresistance.

[0055] Referring specifically to FIG. 7, a packaged semiconductor device112 having at least one lead 114 may be received in a housing 116, suchthat the at least one lead 114 may be in electromechanical contact withan active contact 130. Semiconductor device 112 may be positioned inplace by a lead channel 118 or other orienting means.

[0056] Active contact 130 may comprise a device element 120 and a plate126. The device element 120 and the plate 126 may be constructed from ametallic material, as discussed above. The at least one lead 114 ofsemiconductor device 112 may be in electro-mechanical contact with afirst portion of device element 120. Similarly, a second portion ofdevice element 120 may be in electro-mechanical contact with a signalI/O pad 128 on a load board 122, thus completing a signal path fromsemiconductor device 112 to load board 122. Signal I/O pad 128 may becoupled to a tester or another element.

[0057] Device element 120 may be mechanically bonded to plate 126 via adielectric material 124 such that the two conducting surfaces,comprising device element 120 and plate 126, may be orientated parallelto one another and separated by a distance substantially equal to thethickness of dielectric material 124. Plate 126 may beelectro-mechanically connected to a ground pad 132 on load board 122,such that the construct yields a transmission line structure such as amicro-strip type impedance controlled active contact. It is recognizedthat ground pad 132 may be coupled to a fixed voltage or to a testerWhen connected to a tester, the voltage on ground pad 132 may be variedto provide a time varying impedance signature to the correspondingsignal path.

[0058] In another embodiment utilizing a metal substrate as discussedabove, a precise thickness of metal oxide may be grown on the surface ofdevice element 130 and/or plate 126. The native grown metal oxide mayfunction as the dielectric between device element 130 and plate 126. Itis contemplated that the native grown metal oxide may comprise aninorganic oxide dielectric coating.

[0059] Another embodiment which utilizes the native grown metal oxideconfiguration is shown in FIG. 8. The active contact is generally shownat 150 and may comprise a first contact element 152 and a second contactelement 154. A metal oxide may be selectively grown on contact elements152 and/or 154 such that no metal oxide is present on contactingsurfaces 158A, 158B, or 158C. It is also contemplated that the metaloxide may be grown over the entire outer surface of contacting elements152 and/or 154, and then selectively removed from contacting surfaces158A, 158B, and 158C. Contacting surface 158A may be inelectro-mechanical contact with a lead of a semiconductor device (notshown). Similarly, contacting point 159B may be in electro-mechanicalcontact with a signal I/O pad on a load board (not shown). Finally,contacting surface 158C may be in electro-mechanical contact with aground pad on the load board (not shown).

[0060] In this configuration, first contact element 152 may be placed incontact with second contact element 154, while maintaining electricalisolation therebetween. Various metal plane configurations which allowadjustment and control of the electrical and mechanical interfacecharacteristics are contemplated, including the shape of the contactingelements 152 and 154, the oxide thickness grown thereon, the mutualsurface areas, the plane separation distance, and other parameters.

[0061] Finally, it is contemplate that a window 160, or multiplewindows, may be incorporated into the design of the contacting elements152 and 154. Window 160 may be employed as a conduit for a mechanicallyelastomeric member which may support the active contact 150. Theelastomer member (not shown) may be used to provide an upward biasing ofcontact surface 158A such that as a semiconductor lead is brought intoengagement therewith, the elastomer member may deform thereby permittingactive contact 150 to deflect away from the semiconductor device lead.This may help compensate for non-planer device leads on a correspondingsemiconductor device.

[0062] Another illustrative embodiment that may use the metal substrateconcept discussed above is shown in FIG. 9. In this embodiment, a knownprecise thickness of thermal setting or thermoplastic dielectric 124 maybe laminated between two or more metal plates 120 and 126 in order toachieve the desired electro-mechanical characteristics. It iscontemplated that the two or more metal plates may comprise two or moreisolated circuits. That is, each of the two or more metal plates maycomprise a circuit function. It is further contemplated that adielectric 124 may be constructed from polyimide, epoxy, polycarbonate,polyphenylene sulfide, or any other suitable material. An etch-back ofthe dielectric 124 may be incorporated into the fabrication process tofacilitate ohmic contact on contacting surfaces 158D, 158E, and 158F.

[0063] In another embodiment of the present invention, a ceramicsubstrate may be utilized to create a controlled impedance onpredetermined ones of a plurality of contacts. For example, patternedmetal may be fabricated on a ceramic substrate in such a way as to yieldan impedance controlled electro-mechanical contact. In an illustrativeembodiment, a conventional thin-film multi-layer technology may providea 3-terminal type capacitor wherein the first two terminals maycorrespond to a signal I/O and the third terminal may be in contact witha ground reference. It is also contemplated that the same impedancecontrolled 3-terminal type capacitor could be fabricated by a modifiedmulti-layer thin-film process wherein the conductive phase is depositedon an inert/carrier substrate and patterned for selective oxidationusing chemical anodization, plasma oxidation and/or thermal oxidegrowth, yielding conductive metal patterns within a dielectric. Finally,it is contemplated that the process may be repeated N-times to yield amulti-layer active contact structure of the 3-terminal type capacitor.

[0064] While the last two embodiments primarily provide an illustrativethree terminal capacitor type device, it is envisioned that otherconventional processes may be used to provide resistance, inductance,capacitance, surface acoustical wave filter, and/or a combinationthereof to predetermined contacts. It is further envisioned thatconventional or other processes may be used to provide other activeelements including, transistors, diodes, etc., and/or a combinationthereof to predetermined contacts. Finally, it is envisioned thatconventional or other processes may be used to provide a number ofactive and/or passive elements to provide a circuit which may providepredefined functions, including a microprocessor function topredetermined contacts. That is, in an alternative embodiment,predetermined ones of the above referenced multi-layers each maycomprise an isolated circuit.

[0065] In an illustrative embodiment, as shown in FIG. 10, a ceramicsubstrate 202 having a first contacting surface 158G and a secondcontacting surface 158H may be provided. A metal film may be depositeddirectly on the ceramic substrate. Subsequently, the metal film may bepatterned via an etch or other subtractive process to form a firstconducting surface 204 and a second conducting surface 206. The metalfilm may cover the first contacting surface 158G and the secondcontacting surface 158H to provide a conductive surface thereto. In theillustrative embodiment, there may be a gap between the first conductivesurface 204 and the second conductive surface 206 such that there is noelectrical connection therebetween. A discrete and/or monolithicallyfabricated active components may be affixed such that a first electricalterminal 210 of the discrete and/or monolithically fabricated activecomponent is in electrical communication with the first conductivesurface 204 and a second electrical terminal 212 of the discrete and/ormonolithically fabricated active component 208 is in electricalcommunication with the second conductive surface 206. It is contemplatedthat the discrete and/or monolithically fabricated active component maybe a resistor, capacitor, inductor, diode, or any combination thereof.Further, it is contemplated that the shape of the ceramic substrate andthe pattern of the metal film may be such that a transistor or othermulti-terminal device may be employed. Finally, it is contemplated thata number of resistor, capacitor, inductor, diode, transistors, etc. maybe employed to create a circuit thereon.

[0066] In the illustrative embodiment, the employment of lowconductivity metals or even conductive inks and ceramics, including SiC,may be used to achieve the desired resistance values, with or withoutadditive plating such as gold to minimize contact resistance. However,it is contemplate that an additive plating may be used. The ohmiccontacting surfaces 158G and 158H of active contact 200 may be inelectro-mechanical contact with a semiconductor lead and a load boardterminal, respectively. The first conductive surface 204 may carry anelectrical signal from the semiconductor lead to the first electricalterminal 210 of the discrete or integrated component 208. The signal mayemerge at the second electrical terminal 212 of the discrete orintegrated component 208 and may be carried by the second conductivesurface 206 to the ohmic contacting surface 158H, and finally to a loadboard's signal I/O pad (not shown). In the embodiment shown in FIG. 10,a recess may be fabricated in the ceramic subtract to accommodate thephysical placement of the discrete and/or monolithically fabricatedactive component 208.

[0067] Referring to FIG. 11, another illustrative embodiment which usesthe ceramic substrate, may comprise a 3-terminal capacitor type activecontact. In this embodiment, the contact may comprise a multi-layermonolithic decoupling capacitor. Alternating signal planes 258 andground planes 266 may be fabricated from patterned metal and separatedby inter-layer ceramic dielectric (not shown). This may be accomplishedby repeating a multi-layer thin film process N-times to yield amulti-layer active contact structure as shown in FIG. 11.

[0068] The network of signal planes 258 may be coupled to a firstterminal 254 by a via 256, and to a second terminal 260 by a via 268.The first terminal 254 may be brought into engagement with a lead of asemiconductor device. The second terminal 260 may be in contact with asignal I/O pad 128 on a load board (not shown). The ground network 266may be electrically coupled to a ground reference ohmic contact 262 by avia 264. The ground reference ohmic contact 262 may be coupled to aground reference pad 132 on a load board (not shown). This embodimentmay provide a significant amount of control over a corresponding signalbecause of the relatively large plate area generated by the alternatingconfiguration of the signal and ground planes.

[0069] Having thus described the preferred embodiments of the presentinvention, those of skill in the art will readily appreciate that theteachings found herein may be applied to yet other embodiments withinthe scope of the claims hereto attached.

We claim:
 1. In an electrical connector apparatus for transmitting asignal between a first terminal and a second terminal, the improvementcomprising: (a) a rigid contact for electro-mechanically interconnectingthe first terminal to the second terminal, said contact providing meansfor electrically affecting the signal as the signal is transmittedbetween the first terminal and the second terminal, said electricallyaffecting means being integrated with said contact.
 2. Apparatusaccording to claim 1 wherein said electrically affecting means comprisesan element selected from the group consisting of a resistor, acapacitor, an inductor, a diode, a transistor, a surface acoustical wavefilter, or a gate.
 3. Apparatus according to claim 1 wherein saidelectrically affecting means comprises a circuit.
 4. Apparatus accordingto claim 3 wherein said circuit performs an electrical function. 5.Apparatus according to claim 4 wherein said contact iselectro-mechanically coupled to a plurality of terminals.
 6. Apparatusaccording to claim 5 wherein said function comprises a switch means. 7.Apparatus according to claim 5 wherein said function comprises anamplification means.
 8. Apparatus according to claim 5 wherein saidfunction comprises a conversion means.
 9. Apparatus according to claim 5wherein said function comprises a microprocessor means.
 10. In anelectrical connector apparatus for transmitting a signal between a firstterminal and a second terminal, the improvement comprising: (a) a rigidcontact for electro-mechanically coupling the first terminal to thesecond terminal; (b) electrical affecting means coupled to said contactfor electrically affecting the signal as the signal is transmittedbetween the first terminal and the second terminal; and (c) biasingmeans for engaging said contact such that as said contact is engaged bythe first terminal, said biasing means permits movement of said contactin response thereto.
 11. Apparatus according to claim 10 wherein saidbiasing means comprises an elastomeric element.
 12. Apparatus accordingto claim 11 wherein said electrical affecting means comprises acontrolled impedance.
 13. Apparatus according to claim 12 wherein saidcontrolled impedance comprises an element selected from the groupconsisting of a resistor, a capacitor, an inductor, a diode, atransistor, a surface acoustical wave filter, or a gate.
 14. Apparatusaccording to claim 12 wherein said controlled impedance comprises acircuit.
 15. Apparatus according to claim 14 wherein said circuitperforms an electrical function.
 16. Apparatus according to claim 15wherein said contact is electro-mechanically coupled to a plurality ofterminals.
 17. Apparatus according to claim 16 wherein said functioncomprises a switch means.
 18. Apparatus according to claim 16 whereinsaid function comprises an amplification means.
 19. Apparatus accordingto claim 16 wherein said function comprises a conversion means. 20.Apparatus according to claim 16 wherein said function comprises amicroprocessor means.
 21. Connector apparatus for transmitting aplurality of signals between a plurality of first terminals and acorresponding plurality of second terminals, comprising: (a) a pluralityof rigid contacts for electro-mechanically coupling the plurality offirst terminals to the corresponding plurality of second terminals,predetermined ones of said plurality of contacts comprising: i.electrical affecting means for electrically affecting a correspondingone of the plurality of signals as the corresponding one of theplurality of signals is transmitted between the corresponding firstterminal and the corresponding second terminal; and (b) biasing meansfor engaging said plurality of contacts such that as each of saidplurality of contacts is engaged by a corresponding one of the pluralityof first terminals, said biasing means permitting movement of saidcorresponding contact in response thereto.
 22. Connector apparatusaccording to claim 21 wherein said electrically affecting meanscomprises a controlled impedance.
 23. Connector apparatus according toclaim 22 wherein each of said plurality of contacts electro-mechanicallycouples a plurality of second terminals.
 24. Connector apparatusaccording to claim 22 wherein said controlled impedance comprises: (a) aceramic substrate having an outer surface; (b) a first conductivesurface deposited on a first portion of said outer surface, said firstconductive surface being coupled to a corresponding one of the pluralityof first terminals; (c) a second conductive surface deposited on asecond portion of said outer surface, said second conductive portion notin electrical communication with said first conductive surface, saidsecond conductive surface being coupled to a corresponding one of theplurality of second terminals; and (d) a component having a firstterminal and a second terminal, said first terminal being coupled tosaid first conductive surface and said second terminal being coupled tosaid second conductive surface, whereby the signal passes between saidfirst conductive surface, said first terminal of the component, saidsecond terminal of said component, and said second conductive surface.25. Connector apparatus according to claim 24 wherein said componentcomprises a discrete component.
 26. Connector apparatus according toclaim 25 wherein said component comprises a monolithically fabricatedcomponent.
 27. Connector apparatus according to claim 26 wherein saidceramic substrate has a recess therein to accommodate the physicalplacement of said component.
 28. Connector apparatus according to claim22 wherein said controlled impedance is provided by a first contact ofthe plurality of contacts and a second contact of the plurality ofcontacts, said first contact and said second contact being electricallyseparated by an insulating material.
 29. Connector apparatus fortransmitting a plurality of signals between a plurality of firstterminals and a corresponding plurality of second terminals, saidconnector apparatus being assembled, comprising: (a) a plurality ofrigid contacts for electro-mechanically coupling the plurality of firstterminals to the corresponding plurality of second terminals,predetermined ones of said plurality of contacts comprising: i.electrical affecting means for electrically affecting a correspondingone of the plurality of signals as the corresponding one of theplurality of signals is transmitted between the corresponding firstterminal and the corresponding second terminal; and (b) interchangeablemeans coupled to said plurality of rigid contacts for allowing a firstset of predetermined ones of the plurality of contacts to beinterchanged with a second set of predetermined ones of the plurality ofcontacts after the connector apparatus has been assembled, therebyallowing the connector apparatus to be configurable.
 30. Connectorapparatus for transmitting a signal between a first terminal and asecond terminal, comprising: (a) a contact for electro-mechanicallyinterconnecting the first terminal to the second terminal, said contacthaving at least three ports, a first port of the at least three portsbeing electrically connected to the first terminal, a second port of theat least three ports being electrically connected to the secondterminal, said contact providing an electrically affecting means forelectrically affecting the signal as the signal is transmitted betweenthe first terminal and the second terminal, said electrically affectingmeans being electrically connected to predetermined ones of said atleast three ports.
 31. Connector apparatus according to claim 30 whereinsaid electrical affecting means comprises a transmission line structure.32. Connector apparatus according to claim 31 wherein said transmissionline structure comprises: (a) at least two metal plates wherein said atleast two metal plates are electrically separated by an insulatingmaterial, each of the at least two metal plates being electricallyconnected to a predetermined one of the at least three ports of thecontact.
 33. Connector apparatus according to claim 32 wherein saidinsulating material comprises a thermal-setting dielectric coating. 34.Connector apparatus according to claim 32 wherein said insulatingmaterial comprises a thermoplastic dielectric coating.
 35. Connectorapparatus according to claim 32 wherein said insulating materialcomprises a native grown inorganic oxide dielectric coating. 36.Connector apparatus according to claim 30 wherein said electricalaffecting means comprises a three-terminal capacitor device. 37.Connector apparatus according to claim 36 wherein said three terminalcapacitor device comprises: (a) at least two isolated circuits whereinsaid at least two isolated circuits are electrically separated by aninsulating material, each of the at least two isolated circuits beingelectrically connected to a predetermined one of the at least threeports of the contact.
 38. Connector apparatus according to claim 37wherein said at least two isolated circuits are formed on a ceramicsubstrate using a multi-layer thin film process.
 39. Connector apparatusfor transmitting a plurality of signals between a plurality of firstterminals and a plurality of second terminals, comprising: (a) aplurality of contacts for electro-mechanically interconnecting theplurality of first terminals to the plurality of second terminals,predetermined ones of said plurality of contacts having at least threeports, a first port of the at least three ports of a correspondingcontact being electrically connected to a corresponding one of theplurality of first terminals, a second port of the at least three portsof the corresponding contact being electrically connected to acorresponding one of the plurality of second terminals; and (b)electrically affecting means coupled to each of said predetermined onesof said contacts for electrically affecting a corresponding signal asthe signal is transmitted between the corresponding first terminal andthe corresponding second terminal, said electrically affecting meansbeing electrically connected to predetermined ones of said at leastthree ports of said corresponding contact.
 40. Apparatus forelectrically interconnecting a lead of a device to a terminal spaced ata distance from the lead, comprising: (a) a housing, said housing havingat least one contact receiving slot formed therein, said housing havinga surface intersected by said at least one contact receiving slot, saidat least one contact receiving slot extending substantially parallel toan axis extending between a corresponding lead and spaced terminal; and(b) a contact received within said at least one contact receiving slot,said contact engagable by the lead and further engagable by the spacedterminal, said contact providing means for electrically affecting thesignal as the signal is transmitted between the first terminal and thesecond terminal, said electrically affecting means being integrated withsaid contact.
 41. Apparatus according to claim 40 wherein saidelectrically affecting means comprises an element selected from thegroup consisting of a resistor, a capacitor, an inductor, a diode, atransistor, a surface acoustical wave filter, or a gate.
 42. Apparatusaccording to claim 40 wherein said electrically affecting meanscomprises a circuit.
 43. Apparatus according to claim 42 wherein saidcircuit performs an electrical function.
 44. Apparatus according toclaim 43 wherein said contact is electro-mechanically coupled to aplurality of terminals.
 45. Apparatus according to claim 44 wherein saidfunction comprises a switch means.
 45. Apparatus according to claim 44wherein said function comprises an amplification means.
 47. Apparatusaccording to claim 44 wherein said function comprises a conversionmeans.
 48. Apparatus according to claim 44 wherein said functioncomprises a microprocessor means.
 49. Apparatus according to claim 40wherein each of said at least one contact receiving slot receives aplurality of leads.
 50. Apparatus for electrically interconnecting alead of a device to a terminal spaced at a distance from the lead,comprising: (a) a housing, said housing having at least one contactreceiving slot formed therein, said housing having a surface intersectedby said at least one contact receiving slot, said at least one contactreceiving slot extending substantially parallel to an axis extendingbetween a corresponding lead and spaced terminal; (b) a contact receivedwithin said at least one contact receiving slot, said contact engagableby the lead and further engagable by the spaced terminal; (c) biasingmeans for engaging said contact such that as said contact is engaged bythe first terminal, said biasing means permits movement of said contactin response thereto; and (d) electrical affecting means coupled to saidcontact for electrically affecting the signal as the signal istransmitted between the first terminal and the second terminal.